The present invention relates to apparatus for audio signal processing and, more particularly, to an extremely simple, low cost complete audio processing system utilizable as a compressor.
Many electronic circuits of a complex electronic nature have been developed over the years for processing of audio signals. But owing to their complexity, large size, and sophistication of such circuitry, their use has been primarily limited to studios, the recording industry, radio stations, and in other applications where such attributes pose no problem. Such circuits previously have been used, for example, to modify the sound of musical instruments or human voices when making recordings, as in the record industry. But such prior art circuitry has not been effectively utilizable by ordinary citizens because of high cost, large size, and complexity (typically thousands of dollars for sutido or commercial units) even though it can provide useful modification of audio signals, such as voice or music. There has not existed heretofore small, compact, low cost circuitry for providing dynamic clarification capable of enhancing the quality of audio signals as by ordinary amplification of such signals.
It is an object of the present invention to provide simple, low cost, effective circuitry for providing improvement of audible signals by enhancing clarity and selectively modifying tonal quality.
A further object of the invention is the provision of such circuitry which utilizes dynamic compression and selective enhancement of frequency bands for such purposes.
Another object of the invention is the provision of such circuitry which is low powered, has relatively few components and can be battery operated.
A further object of the invention is the provision of such circuitry which is sufficiently compact as to be housed within an enclosure sufficiently small, compact and lightweight to be carried by hand or in the pocket and to include a small, long-life battery power supply.
Yet another object of the invention is the provision of such circuitry which provides transient filtering, tonal enhancement and signal compression in a most versatile nature, which has simple and effective controls; and which achieves modification and enhancement of audible signals to an extent favorably comparable to expensive studio and commercial electronic equipment.
Other objects of the invention include provision of such circuitry which can be easily expanded in function by duplication for stereophonic or quadriphonic use; which can be readily expanded and adapted to provide selective control over tonal characteristics of signals in numerous frequency bands; and which is compatible with conventional types of audio equipment, such as standard amplifiers, microphones, instrument pick-ups and other conventional audible sound sources.
Among still other objects of the invention may be noted the provision of such circuitry which, when utilized with musical instruments, improves the sound of such instruments including even low quality instruments having otherwise poor tone; which enhances versatility of such instruments by providing selective variation of audible signals produced by the instrument which otherwise would not be available; which is useful with electric guitars or the like for providing tonal clarity which allows a musician to more effectively hear the full effect of his playing the instrument.
Numerous other objects will be in part apparent and in part pointed out hereinbelow.